Exercise equipment, such as, for example, exercise rowing machines, commonly employ hydraulic cylinder units with double-acting pistons to resist movement of pivoted arms to be manipulated for exercise. Commonly, in the case of exercise rowing machines, the rowing arms and the cylinder component of the hydraulic cylinder units have been pivotally connected to the machine frame, and the piston rod has been pivotally connected to the rowing arms to resist movement thereof. To vary the resistance exerted by each hydraulic cylinder unit to arm movement, it has been the practice to adjust the distance from the pivotal connection between the piston rod and arm and the pivotal connection between the arm and the frame. Such adjustment does not provide independent adjustment of the resistance to arm movement in the pulling and pushing directions and normally does not enable fine adjustment of the resistance to be easily accomplished.